Air heating furnace



1 March 1955 J; J. H. BEYERMAN I 2,704,052

AIR HEATING FURNACE Filed April 3, 1951 2 Sheets-Sheet 1 FIGLI INVENTOR J. J: 54 fia erman BY WM 564* FM ATTORNEYS March 1955 J. J. H. BEYERMAN 2,704,062

AIR HEATING FURNACE Filed April 3, 1951 2 Sheets-Sheet 2 INVENTOR J.- J. 9. 3, m

United States Patent AIR HEATING FURNACE Jan Johan Herman Beyerman, Ijsselmonde, Netherlands, assignor to A. de Jong N. V., Vlaardingen, Netherlands Application April 3, 1951, Serial No. 218,992

Claims priority, application Netherlands April 4, 1950 3 Claims. (Cl. 126-99) The present invention relates to furnace heating equipment for rooms and the like.

An object of the invention is to provide a device for the more efiicient heating of air.

A further object of the invention is to provide means for the guidance of the air which will result in improved heat transfer.

A still further object of the invention is to provide a structure to incline the combustion gases in a direction opposite to the air to be heated to secure eflicient heat exhange.

A further object of the invention is to provide means for changing the upward direction of the air fiow so as to direct the heated air substantially horizontally.

With the above and other objects in view which will become apparent from the detailed description below and claimed in the claims, one embodiment of the in vention is shown in the drawings in which:

Fig. l is a side view with a portion broken away at the level of the fire box.

Fig. 2 is a vertical sectional view with parts shown in elevation.

In the various figures, like reference characters indicate like parts.

Referring to Fig. 1, a casing 1 is provided which is positioned vertically and is generally of cylindrical shape. A fire box 2 of cylindrical form is disposed coaxially with the casing 1 and defines an annular space 3 between the part 4 of the casing 1 and the fire box 2.

At the lower part of the fire box 2 there is provided a refractory lining 2a through which extends the oil burner nozzle 5. Opposite to the nozzle 5 there is provided a refractory arch 6 for guiding the flame.

Located below the fire box 2 there is a blower 7 driven by the electric motor 8. The blower 7 draws air through the apertures 9 at the bottom of the air heater and forces such air through the annular space 3.

In order to secure an elficient heat exchange from the fire box to the air passing the same along the passage 3 there is provided on the exterior of the fire box ribs or bafile 10 which are arranged in a helical manner as shown clearly in Fig. 1. The flow of the air is shown by the arrows A in Fig. 2 and due to the construction such air is given a helical rotating movement.

Two concentric annular rows of apertures are provided in the top of the firebox and in the bottom of the gas collection chamber. Tubes 11 extend between the inner lower apertures and the outer upper apertures in alternate relation with tubes extending between the outer lower apertures and the inner upper apertures. These tubes are consequently arranged in an inclined approximately helical manner.

The combustion gases from the fire box 2 escape from the top of the fire box through the apertures provided therein and into the inclined tubes 11. Due to the arrangement of the tubes the apertures provided in the bottom of the gas collection chamber are spaced further apart than at the top of the fire box.

The inclination of the tubes 11 is opposite to the mclination of the baflles 10 whereby the air rotating around the fire box 2 will strike above the top of the fire box 2,704,062 Patented Mar. 15, 1955 against the tubes 11 and thereby secure a better heat exchange.

The heated air will expand and for this reason the air passages extending towards the outlets 12 increase in cross-section as shown particularly at 13. Then the direction of the air flow is changed so that the heated air will again cross the tubes 11 in a substantially transverse ilireclton as shown in Fig. 2 in order to reach the outets In order to secure an improved guiding of the air in the space between the tubes 11, conical members 14 and 15 are provided.

The outlets 12 are uniformly spaced throughout the entire circumference at the top of the casing 1 in order to cause the least resistance to the air flow.

It is thought that the invention and its advantages will be understood from the foregoing description and it is apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing its material advantages, the form hereinbefore described and illustrated in the drawings being merely a preferred embodiment thereof.

What is claimed is:

1. An air heater comprising a generally cylindrically shaped casing having a bottom air inlet and a plurality of circumferentially spaced air outlets adjacent the top of the casing, a cylindrical fire box in said casing in the lower end thereof, said fire box being spaced from the inner wall of said casing and forming therebetween an annular air passage, helically inclined ribs on said firebox in said air passage, said firebox having a top with a plurality of annularly arranged apertures therein, means forming a gas collection chamber in the upper end of said casing, the lower wall of said chamber having a plurality of annularly arranged apertures therein being spaced a greater distance from the axis of said casing than said apertures in the top of said firebox, combustion gas tubes extending upwardly and outwardly from said first named lower apertures to said second named upper apertures to extend in overlying relationship to the annular air passage, said tubes being inclined 1n a direction opposite to the inclination of said ribs so that air passing upwardly through said air passage is heated by said fire box and directed by said ribs to contact said combustion gas tubes at a substantial angle to the axes thereof to provide increased heat transfer to the air.

2. An air heater as claimed in claim 1, said apertures in the top of said firebox being arranged in two concentric annular rows and said apertures in the bottom of said gas collection chamber being arranged in two con-- centric annular rows, said tubes extending between the inner lower apertures and the outer upper apertures in alternate relation with tubes extending between the outer lower apertures and the inner upper apertures.

3. An air heater as claimed in claim 1 and including a conical member centrally arranged on the bottom of said gas collection chamber to direct the flow of the upwardly passing air after having crossed the axes of said tubes a first time in one direction back across said tubes a second time before exhausting from said air outlet to thereby improve heat exchange from said tubes to the air.

References Cited in the file of this patent UNITED STATES PATENTS 251,320 Towne Dec. 20, 1881 764,191 Hoesman July 5, 1904 1,063,264 Jacobson June 3, 1913 FOREIGN PATENTS 504,575 Great Britain Apr. 27, 1939 904,541 France Mar. 5, 1945 

